Epoxy resin cured with a fatty tetraamine

ABSTRACT

USE OF TETRAMINES AS EPOXY RESIN CURING AGENTS.

United States Patent ce US. Cl. 260-47 EN 2 Claims AI S STRACT OF THEDISCLOSURE Use of tetraamines as epoxy resin curing agents.

This application is a continuation-in-part application of Ser. No.410,014, filed Nov. 9', 1964, now US. Pat. 3,418,374 issued Dec. 24,1968.

This invention relates to fatty tetraamines and their use as epoxy resincuring agents.

As discussed in the parent application, it has long been the desire ofchemists to synthesize or to extract from natural substances compoundswhich not only possess the desirable physical and chemical properties ofthe long chain fatty acids, but also contain more reactive groupstherein. With more reactive groups, the fatty compound would not onlyhave good hydrophobic characteristics, but also have high potency,depending upon its reactive group type .for surfactant, for polymeric,or for other cheniical activities.

Among the approaches made toward accomplishing such an objective, thatdisclosed in US. 2,813,113 is typical. There the oxidation of oleic acid[CH (CH )-;CH=CH (CH 0011] to azelaic acid [HO'OC(CH )-;COOH] isdiscussed. Unfortunately, chain cleavage occurs in such oxidation. Thisis undesirable because it is detrimental to the hydrophobic nature ofthe resultant compound.

Roe and Swern of the US. Department of Agriculture, in the Journal ofthe American Oil Chemists Society periodical, volume 37, pages 661 to668 (1960) report that unsaturated fatty acids may be carboxylated withcarbon monoxide. The monoxide adds to the double bond. Such a reactionwould conserve the hydrophobic nature of the 'fatty acid, but apparentlyno further work was done toward discovering new difunctional fattycompounds. This is unfortunate, because, as discussed below, it hasbeefi found that such difunctional compounds may be synthesized rathereasily and they possess many attributes highly desirable for variouschemical technologies.

In the parent application, novel tetraamines are taught which areindicated as being useful as epoxy resin curing agents. The'teachingherein expands on such disclosure.

Accordingly, an object of this invention is to provide novel compoundswhich are useful as epoxy resin curing agents.

Another object is to provide a novel method for curing epoxy resins.

Other objects of the invention will in part be obvious and will in partappear hereinafter.

It has now been found that the novel fatty tetraamines of copendingapplication Ser. No. 410,014 are good epoxy resin curing agents.

Such fatty tetraamines that are useful are those which fall within thefollowing formula:

3,694,409 Patented Sept. 26, 1972 FORMULA 1 omtomn-on-wfl.).wnemomomnn,

where -R is a radical selected from the group consisting of H- and CH3.a=0 to 2 x+y =6 to 22 Among the fatty tetraamines which fall within theabove formula are N"',N"-di- 3-aminopropy1) aminomethylcaprylylamine,N',N"-di (3 -aminopropyl) aminomethylcaprylamine, N",N"-di-(3-aminopropyl) aminomethyllaurylamine, N",N"-di- (3-aminopropylaminomethylmyristylamine, N"',N"-di- (3-aminopropylaminomethylpalmitylamine, N"',N-di- 3 -aminopropyl)aminomethylstearylamine, N",N"-di- (3-aminopropyl)aminomethylarachidylamine, N",N"-di- (3 -aminopropyl)aminomethylbehenylamine, N"',N"-di- 3-aminopropyl)aminomethyllignocerylamine, N', "-di- 3-aminopropyl)aminoethylcaprylylamine, N'", "-di- S-aminopropyl)aminoethylcaprylamine, N'", "-di- (3-amin0propyl) aminoethyllaurylamine, N', "-di- S-aminopropyl) aminoethylmyristylamine,N',N"-di- 3-aminopropyl) aminoethylpalmitylamine, N', "-di-(3-aminopropyl) aminoethylstearylamine, N,N"-di-( 3-aminopropyl)aminoethylarachidylamine, N"',N"-di- 3-aminopropyl)aminoethylbehenylamine, N "',N' -di- (3-aminopropyl) aminoethyllignocerylamine,

or mixtures thereof such as derivable from natural fats and oils such astallow, soybean oil and coconut oil.

The epoxy resin may be in various forms, such as cast sheet, or filmcoating, form. Concentrations of 2 to by weight tetraamine is required.It is mixed with the resin prior to the cure as will be shownhereinafter.

The invention accordingly comprises the several steps and the relationof one or more of such steps with respect to each of the others, and thecomposition possessing the characteristics, properties, and the relationof components which are exemplified in the following detaileddisclosure, and the scope of the invention will be indicated in theclaims.

Reference is now made to the following examples which illustrate theinvention in detail:

EXAMPLE I Mixing and slab preparation The resin and curing agentindicated in Table 1 which follows are weighed together and mixedthoroughly but gently to avoid entrapment of air. The mix is poured intoa mold 9" x 8" x 0.10" and allowed to gel and form a slab. After aperiod of twenty-four hours, the slab surface is checked to determine ifit is tacky. Usually, two slabs of the same formulation are poured. Oneof the slabs is baked in a circulating oven at 300 F. for a definiteperiod of time, while the other is left at room temperature for aEvaluation of cured castings 4 It should be evident from the data ofTable 2 that N"',N"-di-(3-aminopropyl)aminomethylstearylamine is asuperior curing agent to aminomethylstearylamine, even when lesserquantities are used.

Each of the cast slabs prepared as above are evaluated 5 X! i forsolvent and solution stability and hardness and elec- E MPLE HI tricalproperties. Each casting, oven-cured and room- Further testing ofN"',N"-di-(3-aminopropyl)aminocured, is also evaluated for shrinkage.The data of Table methylstearylamine (DMSA) with a commercially avail- 1which follows shows the individual results determined able epoxy resin(Epon 1001, a di-glycidyl ether of bison each formulation: phenol A, assold b Shell Chemical Company of Emery- TABLE 1 Properties oi east sheetof epoxy resin cured with amine curing agents Solvent and solutionstability (percent gain in weight) Physical properties Resin 1 Min-Deion- Hardness Diamine Tolueral 4 4 10% 4 10% 4 ized 4 Shore D electricwt. ratio Cure ene I MIBK spirits Tide NaOH H SO H 0 Shrinkage 10secconstant 70 300 F.; 1.5 hr... 3. 30 3.03 0.19 0.42 0.23 0.92 0.28 Slight73 2.93 70 30 300 F.; 2 hr-- 1.54 0.4 0.03 0.52 0. 23 3.22 0. i1 70 3.1000 13. 79 0. 42 0. 57 0. 51 0. 75 0. 47 70 3. 0e 4. 0s 0. 15 0. 4s 0. 370. 91 0. 2. 99 26. 2 0. 23 0. 01 0. as 0. e1 0. 39 3. 12 3. 03 0. 19 0.42 0. 23 0. 92 0. 2s 73 2. 93 2. 20 74 3.03 2. 17 0 0. 29 0. 22 2. 35 0.34 75 3. 31 0.41 0.03 0.52 0. 23 3.22 0.35 Nil... 70 3.10 0. 59 0.09 0.43 0.30 2.49 0.33 Slight 77 3.03 3.39 0. 00 0.26 0.20 0. 35 0.27 Veryslight 70 3.15 0.36 0.03 0. 39 0.61 3.90 0.79 Nil 78 3.13 3.33 0.07 0.740. 43 1.13 0. 00 Ni] 77 3.11

l Epon 828 as sold by Shell Chemical 00., Emeryvllle, California, adl-glycidyl ether of bis-phenol A.

I 16 to 24 hours exposure.

8 Methyl isobutyl ketone.

l 7 days exposure.

I Commercial household detergent.

0(10)-aminomethylstearylamine.

7 N, N -di-(3-aminopropyl) aminomethylstearylamlne.

I Reaction product of 9(10)-earboxystearie acid and triethylenetetraamlne.

As sold by General Mills, Kankakee, Illinois.

ville, Calif.) will give values such as indicated in Table 3, whichfollows:

TABLE 3 Properties oi a film coating oi epoxy resin cured with DMSA lEpon 1001 (resin) (a di-glycidyl ether of his 100.0

phenol (A) Silicone resin (iiow control agent) 1.00

N, N-di-(3-aminopropyl)aminomethylstearylamlne 13.70

(curing agent).

DMP30 (catalyst) 3.00 Xylene (solvent). 33.33 Cellosolve acetate 35.00.Sweat in time (min 45. Gardner Holdt viscosity. "L". Pot life (R.T.) 8+hrs. Sward hardness aiter 24 hours- 48. Sward hardness after 1 week 60.Impact:

After baking (20 nuns. at 375 F.):

8th inch mandrel Passes. Reverse i p lb. Alter air dry (7 days at roomtemp.):

8t inch mandrel Passes. Reverse impact 160" lb Methyl isobutyl ketoneresistance 72 to 96 hrs.

1 This coating dried in 20 minutes, tack tree in two hours and was driedhard in 4% hours.

55 3 Parts by weight.

TABLE 2 Properties of film coating of an epoxy resin 1 cured with anamine curing agent Physical properties 1 Sward hardness, weeks film hasaged- Impact Flexibility Percent Amine bywt.Cure 12345612346105 10Room..- 3 Pass 4 MSA game 160 160 160 do-.. Fail 5 00m... o.-- DMSA L-14. 14 Bakedm om 1 Epon 1001 as sold by Shell Chemical 00., Emeryville,Calif. a di-glycidyl ether oi bis-phenol A.

From Table 3, it should be evident that Epon 1001, when cured withN"',N-di-(3-aminopropyl)aminomethylstearylamine, has very goodflexibility. Its solvent resistance, even after methyl isobutyl ketoneimmersion for four days, is far better than any other amine tested.

It will thus be seen that the objects set forth above, among those madeapparent from the preceding description, are efliciently attained, and,since certain changes may be made in carrying out the above method andin the compounds set forth without departing from the scope of theinvention, it is intended that all matter contained in the abovedescription shall be interpreted as illustrative and not in a limitingsense.

It is also to be understood that the following claims are intended tocover all of the generic and specific features of the invention hereindescribed, and all statements of the scope of the invention, which, as amatter of language, might be said to fall therebetween.

Now that the invention has been described what is claimed is:

1. A method for curing 1,2-epoxy resin comprising admixing an epoxyresin precursor with 2 to 80% by weight of a fatty tetraamine fallingwithin the following formula:

01!,(0H1).cH-(OH)yN"RoHoHgoH,NR,

NIIIR H: l i'Rg wherein R is a radical selected from the groupconsisting of H" and CH a=0 to 2 x y=6 to 22 and curing the mixture byraising the temperature thereof for a period of time sufficient to causepolymerization.

2. A cured epoxy resin consisting of the reaction product of (1) thereaction product of 2,2-bis-(p-hydroxyphenyl)propane withepichlorohydrin and (2) 2 to by weight of a fatty tetraamine fallingwithin the following formula:

( D- NIIIR Hz I N B,

wherein R is a radical selected from the group consisting of H- and CH11:0 to 2 x+y=6 to 22.

References Cited UNITED STATES PATENTS 3,223,654 12/1965 Nickerson et a1260-2.5 2,865,886 12/1958 Greenlee 260-47 3,418,374 12/1968 Miller et al260-583 WILLIAM H. SHORT, Primary Examiner E. A. NIELSEN, AssistantExaminer US. Cl. X.R. 260-2 N, 18 EP

